One of the guys I work with spent some time in his youth coding Amiga demos in Poland. A friend of his recently found one of his group's old demos on Youtube here. Remember this is with a 14Mhz proc, no 3D acceleration and very little memory and storage.
Nowadays people have machines that are almost 1,000 times faster, not counting their graphics card's GPU. Memory is abundant and portable media can hold loads of information. As an example of how far things have come in the past 15 years, take a look at last year's winner at The Assembly. (Remember, all this is rendered in real-time).